The present invention is directed toward methods for treating a person's teeth and more particularly, toward a carrier and methods for using the carrier where a therapeutic agent may be applied to the carrier which, in turn, is placed on a person's teeth in order to whiten, remineralize, strengthen, reduce hypersensitivity, or otherwise treat the teeth.
Dentists, like other health care professionals, often seek ways in which to improve instruments and procedures in order to provide better care for their patients. For example, dentists have experimented with various procedures for whitening teeth. One such procedure involves dipping a gauze strip into a bleaching material, applying the strip to a patient's tooth, and then exposing the covered tooth to a light source. This procedure, however, is not very effective because the amount of light which passes through the gauze strip is minimal since it is not transparent. A further limitation of this procedure is that because only one tooth is whitened at a time, the procedure is time-consuming, thereby increasing the patient's discomfort and exposure to the light source.
Currently, dentists whiten a patient's teeth by preparing a peroxide solution and coating the teeth with the solution. Once the solution is placed on the teeth, the teeth are exposed to a heat lamp or a laser light in order to heat the peroxide and to accelerate the bleaching process. In order to protect the patient's gums, a rubber sheet, Vaseline, or a light cured gel may be placed on the gums.
There are several disadvantages with the above-described process. For example, the rubber sheet placed over the patient's gums may stretch so that the peroxide solution leaks around the rubber sheet, exposing the patient's gums to the peroxide, thereby causing the patient discomfort. Also, this method cannot be performed on the upper set of teeth and the lower set of teeth simultaneously. Rather, only one set of teeth may be whitened at a time. Another disadvantage is that if a heat lamp is used a substantial amount of time is required in order to effectively bleach the teeth. Thus, the patient is exposed to the lamp for a great deal of time. This can cause extreme discomfort and inconvenience to the patient. Furthermore, the peroxide solution often times cannot be concentrated on the teeth. That is, the solution may drip off of the teeth if too much of the solution is applied or the solution may dry out if too little of the solution is applied.
Another method of whitening teeth is disclosed in U.S. Pat. No. 5,645,428 to Yarborough. This patent discloses using a laser light to activate bleaching agents applied to a patient's teeth. A mixture of peroxide and a first catalyst is prepared and then applied to the teeth. The teeth are then exposed to a laser light which activates the peroxide and catalyst to accelerate the bleaching process without heat. A second mixture of peroxide and a catalyst is then prepared and applied to the teeth. Again, the teeth are exposed to a laser light which heat activates the second mixture to accelerate the bleaching process. This process, however, increases the patient's exposure to laser light.
In yet another system, a peroxide solution may be combined with a gel which acts as a carrier. The mixture is then applied to a person's teeth which are then exposed to a light source. This system may be used by a person without the aid of a dentist or other medical personnel. That is, the peroxide-gel solution may be placed within a plastic mouthguard, such as shown in U.S. Pat. No. 4,990,089 to Munro, which is worn by a person overnight. A problem with this system is that the peroxide-gel solution decreases the effectiveness of the peroxide because generally these solutions are weak.
Also, the use of gel, in any dental office system, decreases the effectiveness of the peroxide because of the gel's opacity. That is, light is not able to pass through to all of the peroxide because of the opacity of the gel. Also, the gel prevents full contact of the tooth with the peroxide solution, thereby decreasing the effectiveness of the peroxide solution.
A home system for whitening teeth is disclosed in U.S. Pat. No. 5,891,453 to Sagel et al. The delivery system described in this patent comprises a strip of flexible material onto which the user may place a quantity of a tooth whitening substance. The flexible strip along with the tooth whitening substance is then placed on the surface of the teeth and is allowed to remain in place for a sufficient period of time to allow the active ingredient within the substance to act on the surface of the teeth. Because the system described in this patent is intended for home use, the concentration of the whitening substance must be relatively low and there is no suggestion of applying ultraviolet light or any other light in order to enhance the whitening function.
In order to remineralize enamel surfaces in a patient's tooth and any subsurface lesions, dentists prepare a compound or solution containing calcium phosphate or mixtures thereof and then contact the compound with the dental tissue. The compound may be placed directly on the tooth or indirectly through a carrier such as a gel, a chewing gum, or a toothpaste applied to the teeth. Once contact is established with the tooth, the calcium phosphate compound will recrystallize to the less soluble apatite form in the lesion and will reform the tooth. These methods, however, are not very effective because they allow only a limited absorption period. Furthermore, the material also has a chance to run off of the dentition, thereby leaving areas of the tooth structure barely touched.
There are many agents which may be used to treat or reduce tooth hypersensitivity. Such agents include potassium nitrate, strontium chloride, and sodium fluoride, to name a few. These agents may be found in a toothpaste or gel. The agents may also be found in mouthwashes or oral rinses. Alternatively, dentists may apply the agent directly to the dentin in the form of a coating, such is the case with regard to sodium fluoride.
For example, U.S. Pat. No. 5,718,885 to Gingold et al. discloses desensitizing teeth using cationically charged colloidal particles which are used in conjunction with a dentally acceptable carrier. The agent and carrier are formulated into any type of oral composition such as an aqueous suspension, dentifrice, gel, mouthwash, lozenge, buccal adhesive patch, gum, or other oral compositions. This composition, however, only allows limited exposure time.
A method for treating and preventing oral infections includes topically applying antiseptics to teeth and gums using mouthwashes and gels. Systemic administration of antibiotics may be prescribed for treating periodontal disease. While both of these methods are effective in reducing oral bacterial counts, the active ingredients rarely remain at the site of infection for an effective period time and at an effective concentration. As a result, the treatment may not be effective. Furthermore, topically applied antiseptics, such as mouthwashes, are easily washed from the site of infection by salivation and routine mastication. Thus, a need exists for an oral composition which is effective in combating growth of infection causing bacteria which is capable of adhering to the site of infection and being retained in the oral cavity.
U.S. Pat. No. 4,496,322 to Sandham et al. discloses a composition for treating dental infections where the composition comprises a varnish containing an antimicrobial agent in a liquid. The composition may be painted on the patient's teeth and allowed to dry thereon. The composition provides sustained release of the agent to the site of the infection over a period of at least four days. This composition, however, may also run off of the teeth while being applied thereto. Thus, an effective amount of the antibiotic may not be retained on the teeth.